[PATCH 1/2] btrfs: add "rescue=usebackuproot" into forced read-only options

According to btrfs(5) man page, all rescue options should require an
read-only mount.

But that read-only check is only introduced for newer rescue options,
not for the pre-existing "usebackuproot" one.

Unify the behavior to match the document.

Signed-off-by: Qu Wenruo <[email protected]>
---
 fs/btrfs/super.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 0a6ce6c19d8c..fef9025a2f76 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -692,7 +692,8 @@ bool btrfs_check_options(const struct btrfs_fs_info *info,
 	bool ret = true;
 
 	if (!(flags & SB_RDONLY) &&
-	    (check_ro_option(info, *mount_opt, BTRFS_MOUNT_NOLOGREPLAY, "nologreplay") ||
+	    (check_ro_option(info, *mount_opt, BTRFS_MOUNT_USEBACKUPROOT, "usebackuproot") ||
+	     check_ro_option(info, *mount_opt, BTRFS_MOUNT_NOLOGREPLAY, "nologreplay") ||
 	     check_ro_option(info, *mount_opt, BTRFS_MOUNT_IGNOREBADROOTS, "ignorebadroots") ||
 	     check_ro_option(info, *mount_opt, BTRFS_MOUNT_IGNOREDATACSUMS, "ignoredatacsums") ||
 	     check_ro_option(info, *mount_opt, BTRFS_MOUNT_IGNOREMETACSUMS, "ignoremetacsums") ||
-- 
2.54.0